HIPAA establishes standard code sets for transactions. These standard code sets include National Drug Codes (NDCs), International Classification of Diseases (ICD-9-CM) diagnoses and inpatient hospital procedures, and the Health Care Finance Administration Common Procedural Coding System (HCPCS). All state-only and proprietary codes are disallowed for use under the HIPAA regulations.

The Department of Health Care Services is currently reviewing their state-only and proprietary codes and will notify providers of any future changes. There are additional standardization requirements for unique identifiers and security that have not yet been finalized by the Department of Health and Human Services and may have significant impact to your organization.

Below is a list of the approved national codes.

Codes	Standards
Diagnosis codes	ICD-9-CM, Volumes 1 and 2
Physician services	CPT-4 (HCPCS level I)
Dental services	CDT-3
Inpatient hospital services	ICD-9-CM, Volume 3
Other health-related services	Alpha-numeric HCPCS
Drugs	NDC
Other substance, equipment and misc. health care items	Alpha-numeric HCPCS